Many electronic control and/or or communication devices, including prior art pillow speakers found in hospital rooms, have a rigid enclosure assembly for physical protection and electrical isolation. For manufacturability, it is commonplace to create the rigid enclosure assembly by providing two complementary rigid shells, and screwing, clipping or gluing the shells together with a printed circuit board (PCB) and any other electronic components inside the rigid enclosure assembly.
Where the electronic device has user control buttons, these are typically incorporated into the device by a switch membrane mounted on one of the shells. A typical switch membrane either comprises the entire switch assembly and a wire harness to drive the signals to the PCB, or it includes the metal domes within its confines and adheres the domes to the PCB to create a normally open switch.
Electronic devices used in health care settings are used on a daily basis, and they are cleaned and disinfected often to prevent the spread of germs. They must be reliable for patient safety reasons. Consequently, they require service and repair more frequently than electronic devices used under less demanding circumstances.
Electronic devices formed according to the prior art are susceptible to damage not only from normal use, but also from liquid cleaning and disinfecting agents. Oftentimes, it is the switch membrane that is damaged, and the entire switch membrane must be removed and replaced, even though an outer graphic overlay of the switch membrane or metal switch domes of the switch membrane may be in perfect condition.
Switch membranes of the prior art, wherein the switch domes are attached to the overlay material, give the electronic device a tactile performance that is less than ideal due to the resistance to movement introduced by the overlay material.
What is needed is an improved electronic device assembly that is easier and less expensive to manufacture, allows for more efficient and less wasteful servicing, and responds better from a tactile standpoint to a user's pushbutton touches.